Objective To investigate the protective effect of acetylated epigallocatechin gallate (AcEGCG) against H2O2-induced oxidative damage to human epidermal melanocytes,and to explore its possible mechanism.Methods Human epidermal melanocytes were isolated and cultured in vitro.Some melanocytes were classified into a H2O2 group induced by H2O2 only,EGCG groups and AcEGCG groups induced by H2O2 after pretreatment with different concentrations of EGCG and AcEGCG,respectively.Three concentrations (10,20 and 40 μmol/L) of EGCG or AcEGCG were used to treat melanocytes for 1 hour in MTS assay and lactate dehydrogenase (LDH) leakage assay and for 2 hours in Western blot assay,while only one concentration (40 μmol/L) was used to treat melanocytes for 0.5,1,2 and 4 hours respectively in flow cytometry assay.Some melanocytes treated with only culture medium and 0.1％ dimethyl sulphoxide (DMSO) served as the control group.After additional culture,MTS assay was performed to determine cell survival rate,flow cytometry to detect the level of reactive oxygen species (ROS) in melanocytes,Western blot to measure the expressions of caspase-9 and caspase-3 proteins.Lactate dehydrogenase (LDH) kit was used to detect the leakage of LDH to culture medium.Statistical analysis was carried out by using one-way analysis of variance for comparisons of multiple group means followed by Student-Newman-Keuls-q (SNK-q) test for multiple comparisons.Results Compared with the control group,the H2O2 group showed significantly decreased cell survival rate (22.99％ ± 0.53％,P ＜ 0.01),but increased LDH leakage level (36.58％ ± 0.73％,P ＜ 0.01),intracellular ROS level (19.08 ± 0.57,P ＜ 0.01),as well as caspase-9 (2.65 ± 0.079,P ＜ 0.01) and caspase-3 (2.36 ± 0.057,P ＜ 0.01) expressions.In comparison with the H2O2 group,the cell survival rate was significantly higher in the 10-,20-and 40-μmol/L AcEGCG groups (79.50％ ± 3.62％,86.52％ ± 5.13％,97.81％ ± 5.21％,respectively,all P＜ 0.01) and EGCG groups (43.19％ ± 1.68％,63.34％ ± 3.60％,70.82％ ± 2.1％,respectively,all P ＜ 0.01).However,the 10-,20-and 40-μ mol/L AcEGCG groups and EGCG groups all showed a significant decrease in the expression levels of caspase-9 (AcEGCG groups:1.44 ± 0.067,1.26 ± 0.059 and 1.10 ± 0.072 respectively;EGCG groups:2.31 ± 0.085,2.13 ± 0.091 and 1.35 ± 0.064 respectively,all P ＜ 0.05) and caspase-3 (AcEGCG groups:1.70 ± 0.053,1.57 ± 0.057 and 1.24 t 0.068 respectively,all P＜ 0.05;EGCG groups:2.09 ± 0.076,1.98 ± 0.093 and 1.79 ± 0.056 respectively,all P ＜ 0.05) compared with the H2O2 group.Similarly,a significant reduction was observed in the leakage level of LDH in these AcEGCG and EGCG groups (all P ＜ 0.01) and in ROS levels in the 40-μmol/L AcEGCG and EGCG groups when compared with the H2O2 group.Conclusions AcEGCG has a stronger protective effect against H2O2-induced oxidative damage to human epidermal melanocytes compared with EGCG,which may be realized through clearance of free radicals,antioxidant effects,and decrease of caspase-9 and caspase-3 expressions.

Objective To evaluate the impacts of the two different gastrectomy methods on the quality of life,complication and prognosis in proximal gastric cancer.Methods One hundred and two cases of proxi-mal gastric cancer in Tung Wah Hospital were collected for retrospective analysis.They were divided into proxi-mal gastrectomy/gastroesophagostomy (PG)group (n =50)and total gastrectomy/esophagojejunostomy (TG) group (n =52),according to the methods of gastrectomy and reconstruction.The postoperative complications, nutritional status and prognosis of the two groups were compared.Results The incidence of reflux esophagitis was obviously higher in PG group than that in TG group (38.0% vs 1 9.2%,χ2 =4.464,P =0.035).No sig-nificant differences were found between the two groups in the incidences of postoperative infection,bleeding and anastomotic leakage (χ2 =0.063,P =1 .000;χ2 =0.001 ,P =0.978;χ2 =0.31 1 ,P =0.577).There were no significant differences between PG and TG group in total plasma protein [(65.26 ±4.1 0)g/L vs (65.33 ± 3.75)g/L,t =-0.402,P =0.688],albumin [(39.76 ±2.1 7)g/L vs (39.59 ±2.04)g/L,t =1 .778,P =0.076],hemoglobin [(1 07.33 ±1 1 .1 0)g/L vs (1 08.09 ±1 1 .1 7)g/L,t =-1 .502,P =0.1 33]and weight loss [1 .00 ~8.00 kg vs 0.50 ~8.20 kg,t =-1 .622,P =0.1 05]in one year postoperatively.All cases were followed-up for 7 months to 1 0 years.No significant differences were found between PG and TG group in the incidences of anastomotic tumor recurrence (4.0% vs 5.8%,χ2 =0.1 71 ,P =0.679),metastasis (24.0% vs 28.8%,χ2 =0.308,P =0.579)and median survival time (53.6 months vs 49.8 months,χ2 =2.564,P =0.1 09).Conclusion Compared with PG group,the incidence of postoperative reflux esophagitis is effectively reduced,and the incidences of malnutrition,tumor recurrence and metastasis and death are not increased in TG group.Hence,TG should be a safe and effective surgery strategy.

Objective To investigate the expressions and the significance among the three markers TGF β1,Survivin and Caspase-3 in intrahepatic bile duct tissues in patients with intrahepatic bile duct stones.Method Total of 130 paraffin section of intrahepatic bile duct tissue were collected at Department of Pathology,The 904th Hospital of Joint Logistic Support Force of PLA from 2013 to 2018.Total of 50 patients with intrahepatic bile duct stones complicated with bile duct strictures (the stenosis group),40 patients with intrahepatic bile duct stones with chronic inflammation (the inflammation group),and 40 patients with normal liver tissues (the normal control group) were included in this study.The expressions of TGF β1,Survivin and Caspase-3 in liver tissues were detected by immunohistochemistry and compared among the 3 groups to find their correlations with the clinicopathological features of the disease of the patients.Results TGF β1 was expressed in 72.0％ of the patients in the stenosis group,37.5％ in the inflammatory group,and 15.0％ in the normal control group.The differences among the groups were significant (P ＜ 0.05);Survivin was expressed in 78.0％ of the patients in the stenosis group,47.5％ in the inflammatory group,and 25.0％ in the normal control group.The differences among the groups were significant (P ＜ 0.05);Caspase-3 was expressed in 10.0％ of the patients in the stenosis group,42.5％ in the inflammatory group,and 75.0％ in the normal control group.The differences among the groups were significant (P ＜ 0.05).Within the stenosis group,TGF β1 was negatively correlated with Caspase-3 (r =-0.882,P ＜ 0.05),and positively correlated with Survivin (r =0.889,P ＜ 0.05).Survivin and Caspase-3 were also negatively correlated (r=-0.923,P＜0.05).Conclusion Abnormal expressions of TGF β1,Survivin and Caspase-3 were involved in the formation of intrahepatic bile duct stones associated with bile duct strictures.

Objective To investigate the disinfection effect and cytotoxicity of intelligent water treatment system on dental unit waterlines (DUWLs), so as to provide basis for the safe and intelligent treatment of DUWLs.Methods From September to October 2017, 4 dental units with intelligent water treatment system were selected as the experimental group, and 4 dental units with municipal water as the source of water supply were used as the control group. The microbiological quality of water samples collected from DUWLs was assessed before and after installation of the intelligent water disinfection system in terms of the total viable counts of microorganisms. Studentt was used to detect the inhibitory effect of water samples on oral microorganism and its toxicity on human oral normal clone.Results After thoroughly disinfecting the waterlines of the dental unit, the bacteria of dental unit in the control group could rapidly grow up to (3.2±1.02) ×103 CFU/ml within 1 weeks, and the experimental group could be maintained at <100 CFU/ml, the difference was statistically significant (P<0.05); In the control group, Pseudomonas aeruginosa, non tuberculous mycobacteria and Acinetobacter baumannii could be detected in the water samples of the control group, while the above pathogens were not be detected in the experimental group. The water samples in the experimental group had significant inhibitory effects on the common bacteria in the dental unit waterlines and in the human oral cavity (P< 0.05), but only a lower cytotoxicity was shown to the epithelial cells of the human oral cavity.Conclusions The intelligent water treatment system can effectively reduce microbial contamination in dental waterlines and provide safe water for patients.

Objective To investigate the clinical and epidemiological characteristics of crayfish associated rhabdomyolysis syndrome in Baiyun District, Guangzhou, and explore the related factors, and to provide evidence for the prevention of crayfish rhabdomyolysis syndrome. Methods The cases of crawfish associated rhabdomyolysis syndrome were found through the foodborne disease surveillance and reporting system, and a field epidemiological investigation was carried out to analyze the clinical and epidemiological characteristics of the cases. Results A total of 25 cases of crayfish associated rhabdomyolysis syndrome occurred in 2020. The intake of crayfish of the cases ranged from 5 to 25, the incubation period was 1 to 9.5h, and the interval from onset to medical treatment was 0.17 to 9h. All the cases had muscle pain, and the content of creatine kinase (CK) in the cases increased to varying degrees (128-17851 U/L). Retrospective cohort analysis of 10 crayfish events found no correlation between the consumption of different parts of crayfish and the incidence of crayfish-related rhabdomyolysis syndrome. Conclusion The incidence of rhabdomyolysis syndrome reported in Baiyun District of Guangzhou is related to the consumption of crayfish, but the pathogenic factors need to be further studied. It is suggested to strengthen the supervision of crayfish breeding, transportation, sales, and processing to ensure the health of consumers.

Objective To evaluate the surgical treatments of refractory sclerosing peritonitis related peritoneal dialysis.Methods Clinical data of 15 patients with refractory sclerosing peritonitis related to peritoneal dialysis treated in the General Surgery Department of the 900th Hospital of the Joint Logistics Support Force of the People's Liberation Army from June 30,2014 to May 30,2018.Among them,5 cases underwent"open abdomen peritoneal catheter removal+intestinal adhesiolysis+abdominal infection flushing and drainage with catheter",4 cases underwent"laparoscopic peritoneal catheter removal+intestinal adhesiolysis+abdominal infection flushing and drainage with catheter",3 cases underwent"laparoscopic peritoneal dialysis catheter removal+abdominal infection flushing and drainage with catheter",2 cases underwent"open abdomen peritoneal dialysis catheter removal+abdominal infection flushing and drainage with catheter",and 1 case underwent"laparoscopic examination combined with laparotomy exploration and removal of lower abdominal catheter+intestinal adhesiolysis+abdominal infection flushing and drainage with catheter".Age,gender,clinical symptoms,abdominal CT examination,peripheral blood routine,blood biochemistry,blood C-reactive protein(CRP),white blood cells,biochemistry,and aetiology of peritoneal dialysis fluid were collected and followed up,and the therapeutic effect was evaluated.Results 15 patients were transferred to the Department of Surgery after ineffective treatment in the Department of Internal Medicine.Preoperatively(after 5 days of antibiotic treatment)compared to before antibiotic treatment,there were no significant changes in blood WBC,blood NEUT％,CRP,and peritoneal fluid WBC(P＞0.05).Laparoscopic exploration or laparotomy exploration was performed,during which the peritoneal dialysis catheter was removed and the abdominal infection focus was cleared.A pelvic cavity washout drainage tube was left in place postoperatively.Fourteen patients had a good recovery after surgery,with effective control of peritonitis symptoms and no complications such as intestinal obstruction or enterocutaneous fistula.After the removal of the peritoneal dialysis catheter,all patients switched to hemodialysis.A comparison of inflammatory markers before and after surgery showed a significant decrease after surgery.Three days postoperatively compared to before surgery(after 5 days of antibiotic treatment),there were no significant changes in blood WBC,blood NEUT％,CRP,and peritoneal fluid WBC(P＞0.05).Seven days postoperatively compared to before surgery(after 5 days of antibiotic treatment),there was a significant decrease in blood WBC[(7.43±2.65)× 109/L VS(10.17±5.24)× 109/L],blood NEUT％[(88.23±9.02)％VS(85.07±11.57)％],and CRP[(152.88±113.01)mg/L VS(114.49±92.97)mg/L](P＜0.05);the peritoneal fluid WBC at 7 days postoperatively showed no significant change compared to before surgery(after 5 days of antibiotic treatment)(P＞0.05).The cases were followed up for at least 22 months,and 13 patients did not experience peritonitis or intestinal obstruction again.One patient died 39 days after surgery due to multiple organ failure,and one patient died from other causes after a 2-year follow-up.Conclusion For refractory sclerosing peritonitis related peritoneal dialysis that is ineffective in medical conservative treatment,On the basis of reasonable and effective antibiotics to control infection,surgical intervention should be actively carried out and surgical methods such as surgery should be used to control the progress of peritonitis,reduce mortality and improve the cure rate.